The objective of this proposal is to establish and maintain a breeding colony of baboons, capable of producing about 150 newborns per year with known pedigree and biological histories, at a cost that is economically practical for domestically reared animals and only slightly higher than the prevailing market value of unconditioned, feral, wild caught baboons. The basic design will be to establish an initial colony of 200 female and 13 male baboons in a semifree-ranging environment. The colony will be contained in a five acre corral type enclosure. Natural mating will be allowed to proceed with a designated portion of the offspring allowed to mature in the colony for replacement breeding stock. Animals of various ages will be harvested during the semiannual capture of the colony for medical review. All requests for utilization of animals from this colony will be approved by a special Colony Review Board.